Three carmakers linked with post-2013 F1 forays
Jean-Francois Caubet, managing director of F1 engine supplier Renault Sport F1, said "Volkswagen, Honda and Hyundai" could launch forays when the turbocharged four-cylinder power plants replace the current 2.4 liter V8s.
His comments are a further sign that engine makers back the FIA's greener rules for 2013, amid Bernie Ecclestone's fears that spectators and sponsors will not appreciate the loss of the current engine note.
As for the aforementioned three, Caubet said they are likely to watch the implementation of the new formula in 2013 and then make a decision.
"I don't think they will come in the first year, because that would be difficult for a car manufacturer," he told motorsport-total.com. "Maybe later."
Renault Sport F1 supplies engines to the Renault, Red Bull and Team Lotus teams.